Lehr



6 Sheets-Srheet 1 Filed Feb. 2o. 1939 F. G. scHwALE Feb. 18, 1941..

Feb.' 1s, 1941. F, SCHWALBE 2,232,638

LEHR

Filed Feb. 20, 1939 6 Sheets-Sheet 2 i N 3mm /zcme Feb. 1s, 1941. F, Q SCHWALBE 2,232,638

w man Filed Feb.v 20,|1939 6 Sheets-Sheet 5 r o in i r V 3mm Feb 18 1941- F. c. scHwALsE l 42,232,6384

` Laux Filed Feb.. zo, A1939 s sheetsneet s Patented Feb. 18, 1941 UNITED STATES PATENT Nori-ICE 6 Claims.

My invention has for its object to provide an efficient means for heating glass-annealing lehrs. The invention particularly provides a lehr'havlng a plurality of hollow radiants heated by flames projected within the radiants and regulated in the extent of their projection by variation of the differential pressure producing the injectment and the withdrawal of the exhaust products of the flame, that may, also, produce, if desired, a regulated movement of heated air from the radiants in the interior of the lehr and desired movement of heated gas between parts or through zones of the lehr.. The invention, thus, provides means for producing a desired heat radiation from the radiants and desired pressures within the lehr in the region of each of the radiants to produce a desired distribution of heat throughout the heating and annealing zones of the lehr.

The invention, also, provides means for producing heated-gas flow at the opposite side walls and along the lehr to maintain uniform desired temperatures within each cross-sectional part of the lehr zones and to produce, if desired, progressive change in temperature in succeeding 25 cross-sectional parts by the radiants.

The invention may be used for annealing a plurality of small articles, which may be supported on a belt that is moved through the lehr, or an extended or a continuous glass sheet may be 30 moved through the lehr by disposing the glass sheet onv rotating rollers. 'I'he invention, also, provides a plurality of adjustable curtains extendingk crosswise the lehr and located above the glass conveyed through the lehr, andope'rative to confine the heat Within the curtain-partitioning parts of the lehr-above the glass, as produced by the heat radiants, and regulatively limiting the gas movements above .the glass'a'nd causing substantially free move- `.1o-ment and distribution of heated gas below thel glass. f

The invention may be contained in structuresvv of different forms and to illustrate -a practical application of the invention, I have selected two lehr structures embodying the invention as examples of the various structures containing the invention and shall describe the selected lehrs hereinafter, it being understood that structures containing my inventionmaybe varied without departing from the spirit of the invention as presented in the claims. The particular lehrs se- 'lected are shown in the accompanying drawings. Fig. 1 is a side view of one form of the lehr structure. Fig. 2 illustrates a part of the heating unit for heating the lehr shown in Fig. 1. Fig. 3

illustrates another part of the heating unit. The parts shown in Figs. 2 and 3 are shown in section to illustrate the interior arrangement of parts of the heating unit. Fig. 4 illustrates a side view of the receiving end of the lehr. Fig. 5 illustrates a 5 top view of the end of the part of the lehrv shown in Fig. 4. Fig. 6 illustrates a view of a section of the lehr taken on the plane of the line 6-6 indicated in Fig. 4. Fig. 7 is a view'of a modified structure for supporting a part of one of the 10 heating units. Fig. 8 illustrates the other form of lehr structure. Fig. 9 illustrates a view of a section taken on the plane of the line 9-9 indicated in Fig. 8. A

The lehr l, shown in the drawings, is divided 15 into parts that may be referred to as the heating zone 2, the annealing zone 3, wherein the heat is maintained above the annealing temperature and is progressively lowered at a controlled rate, and the cooling zone 4, wherein the temperature is 20 lowered at a rapid rate for removal and handling of the .ware. A plurality of heating units l are located in the heating zone 2 while the annealing zone 3 is provided with a plurality of exhaust ilues 9. The ilues 8 may be connected' to a 25 stack, if desired, and provided with dampers 'I for regulating the outwardl movement of the air or gases within the lehr. The flues' 9 coact to move the heated gases or air from the heating zone 2 to the forward end of the controlled cool- 80 ing zone. Also, the cooling zone l is provided with a plurality of shutters 8 for producing a relatively rapid intake of cooling air into the delivery end of the lehr.

Each of the heating units 5 has a hollow 85 opened-end radiant 9, that is located entirely Within the lehr, and a flame pressure regulator, which comprises a burner i2 and air and fuel pressure valves I3 and I4 and pipes that project a'flame into one end of the radiant, and an ex- 40 haust pressure regulator I5, comprising the exhaust and pressure pipes I t and I1 andthe valve I8 that withdraws gases from theother end of the radiant. The flame pressure regulators coact with the exhaust pressure regulators to produce desired flame lengths and corresponding heated areas of the wall surfaces of the radiants and a controlled pressure in the heating zone and, more particularly, within the region of each of the radiants 9. 50

The glass is conveyed through the lehr to progressively/ subject portions to the temperatures maintained in differentparts of the lehr. Glass articles may b e conveyedby a belt, suchk as the beit n, which extends throughout the length of 55 the interior of the lehr and is actuated by a suitable driving means which may be, if desired, connected to a pulley 2| located at therear end of the lehr. The belt moves over a pulley 22 located at the entrance end of the lehr. The part of the belt within the heating zone is supported on the radiants. The remainder of the belt ls supported on suitable rollers located below the bottom wall of the lehr. If the glass is in the form of a sheet, it may be supported on a plurality of rollers and moved through the lehr.

The heating units 5 are temperature controlled according to the temperature produced in sections of the heating zone 2 of the lehr, such as the sections 23, 24, 25, and 26. The flame and exhaust pressure regulators of each section are connected to a source of supply of air under pressure and to a, source of supply of gas through valves that are controlled by the temperature existing in the sections in which the heating units are located. Thus, the heating units 5, located in the section 23, are controlled by a temperature regulator 21; those of section 24 are controlled by a temperature regular 23; those in the section 25 are controlled by a regulator 29; and those in the section 2B are controlled by a. regulator 3|. The regulators 21, 28, 29 and 3| are connected in pairs to pipes 32 and 33 that communicate, respectively, with sources of supply of gaseous fuel and with air under pressure.

The regulators 21, 29, 29 and 3| are provided with two air-regulator valves 34 and 35 and a gas-regulator valve 35 which are mounted side by side and are controlled by an electric motor means 31 that operates the valves of each of the regulators according to the operation of a .thermostatic switch located in the sections of the heating zone 2 with which the regulator valves and the heating units are associated. The valves 34, 35, and 39- are connected together and to their associated motor means 31 to cause variation of the position of their respective movable members as the motor means is actuated. Each of the valves and their associated motor means is provided with an arm 33. A bar 39 is connected to the arms of the valves and the motor means in order to produce angular movement of the movable valve members of the valves 34, 35 and 36 when the motor means 31 is actuated in the manner well known in the art.

The flame pressure regulators are connected to manifolds 4| and 42 and the exhaust pressure regulators are connected to. a manifold 43. The flame and exhaust pressure regulators of each radiant 9 are located on opposite sides of the lehr and the flame pressure regulator of contiguous radants are located on opposite sides of the lehr to produce, by this alternate arrangement, substantial uniformity of heat distribution, cross-sectionally, within the lehr. The manifolds 4| and 42 are located above the lehr and are connected to the valves 36 and 34 respectively. The valves I3 are connected through the pipes 45 and the manifolds 42, .to the valves 34, `and the valves I4 are connected through the pipes 5I and the manifolds 4| and pipes 44 to the valves 35. The manifolds 43 are located at the sides of the lehr and are connected to the valves 35 by means oi the pipes 41.

The radiants 9 are relatively large in diameter and, preferably, formed of relatively thin metal and suitably supported on the bottom wall of the lehr. When heated, they store considerable heat and, thus, retain the heat and waot to maintain uniformity of heat emission within the region in which they are located. Also, by reason of the alternate location of the flame and exhaust pressure regulators of the contiguous radiants with respect to lthe side walls of the lehr they coact to produce uniformity of heat distribution.

The opposite ends of each of the radiants 3 terminate in outwardly flaring flanges 43 and the burner |2 is disposed in -a position with respect to its associated radiant t Project the flame axially into the interior of lthe radiant, Also, the pressure pipe I-i projects well within the interior of the radiant from the opposite open end and axially with respect to the radiant. Each burner I2 has a central pipe 43 that is connected through the valve I3 to .the pipe 45 through which air under pressure is directed from its associated manifold 42 to the end burner. The pipe 43 is located within a sleeve 50, which, preferably, protrudes slightly lbeyond the end oi the pipe 49 and is located within the end of .the radiant 3. The sleeve 50 has an inner diameter larger than 'the exterior diameter of the pipe 43 and forms an annular space surrounding the pipe 49. The pipe 49 and the pipe 50 extend through an opening 39 formed in the wall of the lehr. The outer end of the opening may be covered by a damper 40. Gasris conducted from the manifold 4| through the pipe I and the valve I4 to the end of the burnerV I2 and is projected from the end of pipe 50 into the radiant 3, according to the pressures of the air,

which is conducted through the pipes 45, thev valve I3 and the pipe 43.

The pipe Il projects through the opposite side wall of the lehr and well into the other open end of the radiant. The pipe I9 has an exterior diameter that is considerably less than the inner diameter of the radiant 9. To the outer end of the pipe I5 is connected a T-fixture 53. A flue 54 is connected t-o the T-ilxture 53. The flue 54 extends upwardly and may be connected, if desired, with a. suitable conductor flue for conducting exhaust products to a stack. The T-fixture is, also, provided with a suitable plug 55 through which the pressure pipe I1 extends. The inner end of .the pipe I1 is, preferably, located above the center of the T-nxture 53 to produce a. pressure within the pipe I3 and the end part of the radiant 9 less than atmospheric pressure when the valve Il is opened to connect the pipe I1 with the manifold 43. This operates to draw products of combustion from the radiant 8 at a desired pressure and direct it into the flue 54.

The llame pressurewithin one end part of each radiant is controlled by the valves I3 and I4 and the exhaust pressure within the other end part of each radiant is controlled by the valve Il. Adjustments of the valves I3, I4 and Il produce varied differential pressures within the radiant 3 so that where the ilame pressure produced by the burner fuel is relatively high and the exhaust pressure is low there will be a. pressure higher than atmospheric within the radiant swhich will cause the outward movement of heated gasesl from within the radiant and into the interior oi' the lehr and the flame will be projected well within the radiant. 'I'he relatively small pipe I5 yprevents entrance of the gas flame, when the excess pressures are used. The pipe I6 may be provided, if desired, with a reticulated screen 59 that will cool the gases and prevent entrance of the flame into the exhaust pipe 54 to a material degree.` If the flame pressure isincreased the areaheated by the flame will be extended and, consequently, the area of heat radi-v ation from the outer surface cf the radiant will be extended. Where, on the other hand, the

pressure produced by the flame pressure isrelatively -low andthe exhaust pressure is relatively.

I outwardly from the lehr.

Thus, the invention provides a means forregulating and -directingl movements of the air within the lehr in accordance with the desires of the lehr operator, such as by supplying pressure to the heated zone to produce either a slight outward air movement at the entrance end of the lehr and, thus, prevent the inward movement of cool air into the lehr, or a movement of a larger quantity of heated gas to the annealing zone as may be determined by the adjustment of the valves, Il and I'B controlling the gas, air, and exhaust flow to and from the various radiante located in said various zones. The invention, also, provides means for regulating vand directing the movements of ,lehr air withinthe'immediate vicinity` of each individualradiant, as well as in zones, to, thus, obtain the maximum efficiency from the heat given off by each radiant and in accordance with the character of the article passing through the lehr.

As the articles are conveyed on the belt Il, they willbe can'ied through the heated zones and progressively heated according to the conditions that exist inthe different parts of the heated zone to 40 above the required critical temperature. In the annealing zone the articles may be maintained at a substantially uniform temperature above the required critical temperature and then gradually cooled as they progress through the annealing zone until they reach the cooling zone where they are more rapidly cooled. The articles are then removed from the belt i9.

The radiants may be supported upon ridges formed of refractory blocks, such as the blocks I 50; or they may be supported by means of rollers,

such as the rollers 51, that-are supported on the bases 58 that are located on the bottom wall of the lehr. The belt I9 may, in the form shown .in Fig. 6, slide over the radiants l, or the radiante may roll on'the rollers 51 'as the belt i! is moved through the-lehr; The flanges Il at' the ends of the radi'ants operate to retain the belt I9 in proper position with respect to the radiants I whether the radiants 9 are held stationary, as in the form 60 shown in Fig. 6, or the radiants rotate, as in the form shown in Fig.,7.

In the form of construction illustrated in Figs.

8 and 9, thelehr is heated by means of the radiants 9, which are provided with the same gas pressure and exhaust pressure regulative means to produce the desired pressure differentials within the radiante and, particularly, at the open ends of the radiants, and which may be either positive or negative to produce the desired flow of heated gas along the lehr, as' may be determined by the pressures that exist at the open ends of the lehr, whereby the glass in the heating' and cooling zones of the lehr may be progressively modied, and the desired temperature may be malntained in the centralzone, as may be required to anneal the glass. The radiants in the lehrs shown in Figs. 8 and 9, instead of being supported at opposite ends, either by piers or ridges'located Y on the bottom wall, as shown in the form of lehr illustrated in Figs. l to '1, may be flxedly support- I ed at one end by means of a bracket Il, and lo-Y cated on rollers l2 that may be supported on suitable shafts extendi lengthwise the lehr. The rollers I! permit extended movements of an end part of each radiant dueto change in temperal0 ture of the radiant as it is heated by the fuel gas that is introduced into one end of the radiant.

A plurality of rollers Il are located above the radiants l. The rollers '0l extend crosswise the lehr and are located in spaced relation, substan-` II I tially throughout the zones of the lehr. The rollers OI are relatively closely disposed to each other to support sheet glass that may be directed or fed to the lehr as it is drawn from the forehearth of a furnace and directed through the lehr by the 20 rollers Il to anneal the glass. As the glass is*4 delivered from the lehr, it is cut into commercial sizes.

The broad ribbon of glass Il `is conveyed through the lehr by the rotation of the rollers 6I. The rollers II maybe rotated by any suitable 'driving means, such as the electric motor 1l. The

motor is connected 'through a reducing gear, located in the gear box 12, the shaft 13, and the bevel and spur gear wheels 1l and 15, to the 80 shaft 11 that extends along one side of the lehr. The shaft 11 is provided with a plurality of worms 1t that .mesh with the worm gear wheels 16, mounted on the rollers Il, for causing the rollers tl to rotate at the same rate and, thus, convey a5 the sheet glass from near one end of the lehr to the other end of the lehr. If desired, a plurality of driving motors, such as the motor and its transmission gear, may be distributed along the lehr because of the length of the lehr to re- 40 lieve the torque' on the shaft 11. A

lEndparts 1I of the rollers 6l that protrude from the sides of the lehr, are rotatably supported in bushings Il located in bearing blocks or heads l2 which may be mounted on I-beams 45 83 that are supported by suitable standards t4. The heads I2, located on one side of the lehr, may be provided with gear boxes "in which the worm gears 1C and 1I are located, and, where the driving connection is made with the motor 1|, 50 the gear boxes l! may be slightly enlarged to enclose the bevel gears 14 and 15. The heads l2 of the other side of the lehr may, also, be supported on an I-beam I3 and by standards 84.-: The motor shelf or bracket Il that may be secured to one of the standards Il.

The rollers Il are', preferably, formed hollow and the end vparts 19 are partitioned from the central parts of the rollers l! by the walls It 60 .to prevent heat radiation from the central por- A tions of the rollers to the bearings that support the rollers. The rollers may be formed in sections that are suitably secured together, as by interfltting parts that are welded together, 65 the length of the central sections of the rollers having lengths such as to locate the partitioning walls It within the walls of the lehr, and the end sections or parts 1I having lengths to locate theA end parts 1l of the rollers in the heads l2. 70 The-lehr is provided with a plurality of sheet metal curtains Il that extend crosswise the lehr and are supported on and connected to the rods t2, but are oscillatably supported in sleeves Il that are located in the side walls of the lehr, The 75 1| may be supported on a suitable 65 curtains are spaced along the zones of the lehr and extend from the top wall of the lehr to near the glass and, thus, subdivide the zones into sections where the heat oi' the gas maintains a high temperature above the glass. particularly at the top wall of the lehr, and the cooler air is conveyed beneath the edges of the curtains, according to the adjustment of the curtains.

The curtains 9i are adjusted relative to the glass, by movement of the rods 92. The rods are moved by the arms 94, each arm being connected to an end 'o1' each oi the rods 92. The arms 9| move over the sectors 85 having spaced openings 96 in which pins 81, carried by the arms 94, may be inserted to adjustably position the lower edges of the curtains withreference to the glass and, thus, control movement or discharge of the cooler gas within the lehr and intermixture of the heated and cooler gases within the lehr and the desired temperature within the sections of the lehr. t

I claim:

1. In a lehr, a tempering chamber for tempering glass articles; a plurality of hollow radiants located in the tempering chamber, each radiant having openings connecting the interior of the radiant with the interior of the tempering chamber; a ame pressure regulator for projecting a flame of desired pressure into each of the radiants; means, individual to each radiant, for withdrawing products of combustion therefrom and for varying the pressure at the openings to the tempering chamber relative tothe 'pressure produced therein by the flame pressure regulator to vary the zonal temperature in the tempering chamber; and means for moving glass articles through the tempering chamber.

2. In a lehr, a tempering chamber for temperlng glass articles; a plurality of hollow, heatcontrolled radiants, located in -the tempering chamber, for forming different zonal temperatures n the chamber, each radiant having openings connecting the interior of the radiant with the interior of the tempering chamber; a flame pressure regulator for projecting a flame of desired pressure into each of the radiants; an exhaust pressure regulator, individual to each radiant, for withdrawing products oi combustion therefrom and cooperable with the llame pressure regulator to vary the pressure produced in the tempering chamber and in the region of each radiant and cause movement of the heated gases -in the chamber and maintain the zonal temperatures; and means for moving glass through the tempering chamber.

3. In a lehr, a tempering chamber for tempering glass articles; a plurality of hollow. heatcontrolled radiants, located in the tempering chamber, for forming different zonal temperatures in the chamber. each radiant having an opening for connecting the interior of the radiant with the interior of the tempering chamber; a

burner having means for directing a dame into each of the radiants; a combustion-gas exhaust pipe protruding to a point within each of the radiants and having means, individual to each radiant, ior'withdrawing products of combustion from within the radiant, in the vicinity of the opening, to vary the pressure at the opening and control the movement of the heated gases in the chamber; and means for moving glass through the tempering chamber.

4. In a lehr, a tempering chamber for tempering glass articles; a plurality of hollow radiants located within the tempering Ychamber and having open ends, the end edges spaced from the side walls of the tempering chamber; a burner for Vdirecting a name into one end of` each of the radiants; a combustion-gas exhaust pipe protruding through the other end oi each of the radiants to apoint within the radiant; means, individual to each radiant and connected to said pipe, certain of each of said means for withdrawing products of combustion from within the radiant and other of the said means for withdrawing gas from the radiant and the tempering `chamber to control the now of heated gas in the tempering chamber; and means for moving the glass through the tempering chamber.

5. In a lehr, a tem',-:ring chamber for tempering glass articles; a plurality of hollow radiants located in the tempering chamber, each radiant having openings connecting the interior of the radiant with the interior of the tempering chamber; a flame pressure regulator for projecting a iiame of desired pressure into each of the radiants; means, individual to each radiant, for withdrawing products oi' combustion therefrom and for varying the pressure at the openings to the tempering chamber relative to the pressure produced therein by the iiame pressure regulator to vary the zonal temperature in the tempering chamber; and means for supporting the glass articles above the radiants and for moving the glass articles through the tempering chamber over the radiants.

6. In a lehr, a tempering chamber for tempering sheet glass; a plurality of hollow radiants located in the tempering chamber, each radiant having end openings connectingthe interior of the radiant l'withthe interior of theV tempering chamber; al flame pressure regulator'fior `projeci',-y ing a flame o! desired pressure into each ofthe.,A

radiants; an exhaust pressurereg'ulator for withdrawing products oi' combustion fromv each,

radiant to vary the pressure at'theopenings of the radiants and "the zonaltemperaturev in the tempering chamber; l'a' pluralityi of rollers for supporting the glasssin the tempering.' chamber above the radiants; and meanstinterconnecting the rollers lior rotating the' rollersy to, move the sheet glass through the zones of the tempering 0,0i

chamber.

FRANZ G. 

